wintun: defer requires unique variable

diff --git a/tun/wintun/wintun_windows.go b/tun/wintun/wintun_windows.go
index 8b8524226bdf000345a5faa4d36d43642aa25f42..2f8fcc1e4cde5f67daff7dc321b8e75652c90860 100644 (file)
--- a/tun/wintun/wintun_windows.go
+++ b/tun/wintun/wintun_windows.go
@@ -262,13 +262,13 @@ func CreateInterface(description string, requestedGUID *windows.GUID) (wintun *W
        // Register device co-installers if any. (Ignore errors)
        devInfoList.CallClassInstaller(setupapi.DIF_REGISTER_COINSTALLERS, deviceData)
 
-       var key registry.Key
+       var netDevRegKey registry.Key
        const pollTimeout = time.Millisecond * 50
        for i := 0; i < int(waitForRegistryTimeout/pollTimeout); i++ {
                if i != 0 {
                        time.Sleep(pollTimeout)
                }
-               key, err = devInfoList.OpenDevRegKey(deviceData, setupapi.DICS_FLAG_GLOBAL, 0, setupapi.DIREG_DRV, registry.SET_VALUE|registry.QUERY_VALUE|registry.NOTIFY)
+               netDevRegKey, err = devInfoList.OpenDevRegKey(deviceData, setupapi.DICS_FLAG_GLOBAL, 0, setupapi.DIREG_DRV, registry.SET_VALUE|registry.QUERY_VALUE|registry.NOTIFY)
                if err == nil {
                        break
                }
@@ -277,9 +277,9 @@ func CreateInterface(description string, requestedGUID *windows.GUID) (wintun *W
                err = fmt.Errorf("SetupDiOpenDevRegKey failed: %v", err)
                return
        }
-       defer key.Close()
+       defer netDevRegKey.Close()
        if requestedGUID != nil {
-               err = key.SetStringValue("NetSetupAnticipatedInstanceId", requestedGUID.String())
+               err = netDevRegKey.SetStringValue("NetSetupAnticipatedInstanceId", requestedGUID.String())
                if err != nil {
                        err = fmt.Errorf("SetStringValue(NetSetupAnticipatedInstanceId) failed: %v", err)
                        return
@@ -319,17 +319,17 @@ func CreateInterface(description string, requestedGUID *windows.GUID) (wintun *W
        // DIF_INSTALLDEVICE returns almost immediately, while the device installation
        // continues in the background. It might take a while, before all registry
        // keys and values are populated.
-       _, err = registryEx.GetStringValueWait(key, "NetCfgInstanceId", waitForRegistryTimeout)
+       _, err = registryEx.GetStringValueWait(netDevRegKey, "NetCfgInstanceId", waitForRegistryTimeout)
        if err != nil {
                err = fmt.Errorf("GetStringValueWait(NetCfgInstanceId) failed: %v", err)
                return
        }
-       _, err = registryEx.GetIntegerValueWait(key, "NetLuidIndex", waitForRegistryTimeout)
+       _, err = registryEx.GetIntegerValueWait(netDevRegKey, "NetLuidIndex", waitForRegistryTimeout)
        if err != nil {
                err = fmt.Errorf("GetIntegerValueWait(NetLuidIndex) failed: %v", err)
                return
        }
-       _, err = registryEx.GetIntegerValueWait(key, "*IfType", waitForRegistryTimeout)
+       _, err = registryEx.GetIntegerValueWait(netDevRegKey, "*IfType", waitForRegistryTimeout)
        if err != nil {
                err = fmt.Errorf("GetIntegerValueWait(*IfType) failed: %v", err)
                return
@@ -343,25 +343,25 @@ func CreateInterface(description string, requestedGUID *windows.GUID) (wintun *W
        }
 
        // Name ourselves.
-       deviceKey, err := registry.OpenKey(registry.LOCAL_MACHINE, wintun.deviceRegKeyName(), registry.SET_VALUE)
+       deviceRegKey, err := registry.OpenKey(registry.LOCAL_MACHINE, wintun.deviceRegKeyName(), registry.SET_VALUE)
        if err != nil {
                err = fmt.Errorf("Device-level registry key open failed: %v", err)
                return
        }
-       defer deviceKey.Close()
-       err = deviceKey.SetStringValue("DeviceDesc", deviceTypeName)
+       defer deviceRegKey.Close()
+       err = deviceRegKey.SetStringValue("DeviceDesc", deviceTypeName)
        if err != nil {
                err = fmt.Errorf("SetStringValue(DeviceDesc) failed: %v", err)
                return
        }
-       err = deviceKey.SetStringValue("FriendlyName", deviceTypeName)
+       err = deviceRegKey.SetStringValue("FriendlyName", deviceTypeName)
        if err != nil {
                err = fmt.Errorf("SetStringValue(FriendlyName) failed: %v", err)
                return
        }
 
        // Wait for network registry key to emerge and populate.
-       key, err = registryEx.OpenKeyWait(
+       netRegKey, err := registryEx.OpenKeyWait(
                registry.LOCAL_MACHINE,
                wintun.netRegKeyName(),
                registry.QUERY_VALUE|registry.NOTIFY,
@@ -370,20 +370,20 @@ func CreateInterface(description string, requestedGUID *windows.GUID) (wintun *W
                err = fmt.Errorf("makeWintun failed: %v", err)
                return
        }
-       defer key.Close()
-       _, err = registryEx.GetStringValueWait(key, "Name", waitForRegistryTimeout)
+       defer netRegKey.Close()
+       _, err = registryEx.GetStringValueWait(netRegKey, "Name", waitForRegistryTimeout)
        if err != nil {
                err = fmt.Errorf("GetStringValueWait(Name) failed: %v", err)
                return
        }
-       _, err = registryEx.GetStringValueWait(key, "PnPInstanceId", waitForRegistryTimeout)
+       _, err = registryEx.GetStringValueWait(netRegKey, "PnPInstanceId", waitForRegistryTimeout)
        if err != nil {
                err = fmt.Errorf("GetStringValueWait(PnPInstanceId) failed: %v", err)
                return
        }
 
        // Wait for TCP/IP adapter registry key to emerge and populate.
-       key, err = registryEx.OpenKeyWait(
+       tcpipAdapterRegKey, err := registryEx.OpenKeyWait(
                registry.LOCAL_MACHINE,
                wintun.tcpipAdapterRegKeyName(), registry.QUERY_VALUE|registry.NOTIFY,
                waitForRegistryTimeout)
@@ -391,8 +391,8 @@ func CreateInterface(description string, requestedGUID *windows.GUID) (wintun *W
                err = fmt.Errorf("OpenKeyWait(HKLM\\%s) failed: %v", wintun.tcpipAdapterRegKeyName(), err)
                return
        }
-       defer key.Close()
-       _, err = registryEx.GetStringValueWait(key, "IpConfig", waitForRegistryTimeout)
+       defer tcpipAdapterRegKey.Close()
+       _, err = registryEx.GetStringValueWait(tcpipAdapterRegKey, "IpConfig", waitForRegistryTimeout)
        if err != nil {
                err = fmt.Errorf("GetStringValueWait(IpConfig) failed: %v", err)
                return
@@ -405,28 +405,17 @@ func CreateInterface(description string, requestedGUID *windows.GUID) (wintun *W
        }
 
        // Wait for TCP/IP interface registry key to emerge.
-       key, err = registryEx.OpenKeyWait(
+       tcpipInterfaceRegKey, err := registryEx.OpenKeyWait(
                registry.LOCAL_MACHINE,
-               tcpipInterfaceRegKeyName, registry.QUERY_VALUE,
+               tcpipInterfaceRegKeyName, registry.QUERY_VALUE | registry.SET_VALUE,
                waitForRegistryTimeout)
        if err != nil {
                err = fmt.Errorf("OpenKeyWait(HKLM\\%s) failed: %v", tcpipInterfaceRegKeyName, err)
                return
        }
-       key.Close()
-
-       //
-       // All the registry keys and values we're relying on are present now.
-       //
-
+       defer tcpipInterfaceRegKey.Close()
        // Disable dead gateway detection on our interface.
-       key, err = registry.OpenKey(registry.LOCAL_MACHINE, tcpipInterfaceRegKeyName, registry.SET_VALUE)
-       if err != nil {
-               err = fmt.Errorf("Error opening interface-specific TCP/IP network registry key: %v", err)
-               return
-       }
-       key.SetDWordValue("EnableDeadGWDetect", 0)
-       key.Close()
+       tcpipInterfaceRegKey.SetDWordValue("EnableDeadGWDetect", 0)
 
        return
 }